[jdk17] Integrated: 8269580: assert(is_valid()) failed: invalid register (-1)

[Jatin Bhateja]

On Tue, 29 Jun 2021 15:34:18 GMT, Jatin Bhateja <jbhateja at openjdk.org> wrote:

> - Assertion fails during emit phase of rep_stos instruction pattern on targets not supporting AVX512BW feature.
> - Pattern is selected under following predication logic.
>  predicate(!((ClearArrayNode*)n)->is_large() &&
>               (UseAVX <= 2 || !VM_Version::supports_avx512vlbw()));
> - Encoding block of this pattern passes a  knoreg opmask register having a default encoding of -1,  this later causes an assertion failure while assembling instruction operating over this register. 
> - Existing pattern rep_stos_evex should be able to handle case for AVX512 targets as instructions operating of opmask registers are anyways guarded by target feature checks.

This pull request has now been integrated.

Changeset: 4bbf11d4
Author:    Jatin Bhateja <jbhateja at openjdk.org>
URL:       https://git.openjdk.java.net/jdk17/commit/4bbf11d4a9d00c13149135de3a0e8138f58bcb52
Stats:     4 lines in 2 files changed: 0 ins; 0 del; 4 mod

8269580: assert(is_valid()) failed: invalid register (-1)

Reviewed-by: kvn, dlong

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PR: https://git.openjdk.java.net/jdk17/pull/172